Oh dear!
Your doc is wrong in pretty much everything she said!
1 You are right that Premique is for post-menopause so unless you are 54 and have been using HRT for say a year or more, then it's not appropriate to switch to conti HRT unless she has suggested a trial to test whether you are post-meno. Even so you can stay on cyclical HRT if you want to.
2 The oestrogen in premique is completely different from that in Femoston. Premique contains the horse oestrogens and is a mix of oestrogens, stronger than our own oestrogen. Femoston contains estradiol which is bio-identical with oestrogen our body produces. In addition Premique is only available as low dose whereas Femoston 2/10 is medium dose.
3 There are several alternatives to the Mirena coil. If you go to the menu and look at the HRT options you will find them. There are other combi tablets:
https://www.menopausematters.co.uk/perimeno.php although all at the same dose of oestrogen. However you can take oestrogen separately from the progestogen - oestrogen in the form of tablet, patch or gel, and progestogen as Provera tablets or utrogestan capsules (bio-identical progesterone). These are listed in the same section of the menu. Also depending on your age you might be able to get the Mirena fitted (should you want one) at a family planning clinic or whatever they're called now!
Hope this helps and do ask again if you need any further info
Hurdity x